TAKE - remove use of -funsigned-char from xfs

This makes xfs and spinlock debugging in the same kernel possible.
I have run some fairly heavy stress on this and it all works for me.
I found the spots in xfs which were using just char as a data type
which appear to matter.
Date: Wed Jan 23 15:48:25 PST 2002
Workarea: jen.americas.sgi.com:/src/lord/xfs-linux.2.4
The following file(s) were checked into:
bonnie.engr.sgi.com:/isms/slinx/2.4.x-xfs
Modid: 2.4.x-xfs:slinx:110094a
linux/fs/xfs/xfs_log_priv.h - 1.78
- Stop using char as the type for some fields in here, go to explicit
use
of a __uint8_t.
linux/fs/xfs/Makefile - 1.133
linux/fs/xfs/linux/Makefile - 1.47
- Remove the explicit setting of -funsigned-char from the makefile